Paystation telephone system



June 1, 1937. F. APPELIUS PAYSTATION TELEPHONE SYSTEM Filed Feb 15, 1956J;- INVENTOR. FRITZ APPELIUS WW I ATTORNE Patented June 1, 1937 UNITEDSTATES PATENT FFHQE PAYSTATION TELEPHONE SYSTEM Application February 13,1936, Serial No. 63,707 In Germany February 21, 1935 9 Claims.

The invention relates to a circuit arrangement for pay stations adaptedfor short distance working, As is known in such pay stations the feeaccording to the call number which is to be dialled must be insertedbefore beginning to dial. The control as to whether the fee insertedcorresponds to the value of the call set up, can beqeifected either inthe paystation or by switching devices in the exchange.

The present invention relates to a circuit arrangement in which feecontrol takes place in the exchange. The control device in the exchangeconsists fundamentally of a discriminating switch to be set up by thedialled impulses, and a switch which is set by fee impulses whosesetting must correspond with the setting of the discriminating switch ifthe call is to be switched through. The setting of the switch which isset by the fee impulses involves no difiiculties if the setting is to beefiected by fee impulses of one kind. In order to make the pay stationmore convenient to use it must be able to be operated by coins ofvarious values. A relatively simple construction of the pay stationapparatus is possible if for each type of coin a particular fee impulsecontact is closed in the pay station. Moreover, the switchingarrangements may be such that it can be left to the subscriber to decidewhen to insert the coins, i. e. either before or after removing thereceiver.

Since not only short distance and local calls with automatic paymentcontrol may be set up from the pay station, but also long distance callsin which the supervising operator is informed of the amount of the suminserted by means of audible signals produced in the pay station, theswitching arrangements must be such that the impulses produced by theoperation of the fee impulse contacts on the insertion of coins, andalso the audible signals produced by the insertion of coins, are notdistorted in their transmission to the exchange. Crackling noisesproduced by the opening and closing of the fee impulse contacts mustalso be kept at a minimum. These various demands are met by the!invention in that the fee impulse contacts which are constructed assuccessively closing contacts connect earth potential transitorily tothe point of symmetry at the pay station over various resistancescorresponding to the value of the inserted coins. In order to make thecontact closing, which produced by the fee impulse contacts, efiectivefor setting the fee indicating switches in the exchange, according tothe invention relays are connected to the line in series,

which possess two differential windings of which one winding isconnected to one branch of the line and the other winding to the otherbranch of the line. .The constants of these fee impulse relays are sochosen that one of the relays only energizes when subjected to strongcurrent. Moreover, a further relay is connected in series with onewinding of the fee impulse relays and is energized over the exchangeloop when the receiver is removed, no influencing of the fee impulserelays taking place on account of the differential arrangement of thewinding of these relays. By means of the fee impulse contacts in thepaystation which connect earth potential to the line over variousresistances according to the value of the'inserted fee one or both ofthe fee impulse relays are caused to energize. Each of the two feeimpulse relays controls a fee selector in the exchange. In order totransmit the correct value corresponding to the sum of the inserted feein coin units to the switch associated with the discriminator, specialswitching means are necessary. For this purpose the invention makes useof an auxiliary selector which first takes up the complementary steps ofthe one feed selector and transmits its complementary steps to thetotalling switch and at the same time converts the fee value taken upfrom the fee selector into units while simultaneously subtracting thesetting of the other fee selector which is produced by the simultaneousenergization of both fee impulse relays, by means of a correspondingwiring of the contacts of the auxiliary selector to those of thetotalling switch. The transmission of the setting of the other feeselector takes place similarly by means of the auxiliary selector inthat the auxiliary selector again takes up the complementary steps inthis second fee selector and then transmits its complementary steps tothe totalling switch.

The manner in which the individual switching operations take place isindicated by the embodiment described below.

Fig. 1 represents switching arrangements in the pay station and- Fig. 2those in the exchange. The references in Fig. l have the followingsignificance:.

lI-IU and 2HU are the contacts which are operated by the switch hook.nsa is the dial ofinormal contact. nsi is the dial impulse contact. Thecollecting magnet is indicated by KM and on energizing it directs thecoins which are in an intermediate container into the collecting box. SMis a locking magnet which efiects the return of the coins present in theintermediate container on hanging up the receiver in dependence upon theswitching operation in the ex change. On the insertion of 10 pfg. piecesthe contact gl is transitorily closed, and on inserting a 50 pfg. piecethe contact 950 is transitorily closed. W2 is a resistance. Dr is achoke coil. The speech microphone is indicated by Ms and the gongmicrophone by Mk. F is the receiver and In an induction coil. In Fig. 2the contacts of the relays are indicated by corresponding small lettersand are differentiated by prefixed arabic numerals. The wipers of theselectors are differentiated by roman numerals. The rotary magnets ofthe selectors are given references consisting of several letters ofwhich the first is D and the remaining letters corresponding to theswitch wipers controlled by the magnets.

It will be assumed that the short distance, calls are defined by a twodigit characterizing number. The fee which is to be paid will be assumedto lie between 10 pigs. and 3.50 marks. This fee can be paid as desiredin 10 pig. and 50 pig. pieces. It is, of course, also possible for afurther kind of coin to be used if corresponding devices are provided inthe pay station whereby on the insertion of a coin of high value the feeimpulse contact is operated a number of times. Such devices are known.It will be assumed that a connection whose call number has thecharacterizing number 08 in the first two digits of the call number canonly be set up by the insertion of a fee amounting to 2.70 marks by thecalling party. In the example to be considered the calling party inserts22 10 pig. pieces and one 50 pfg.. piece. The switching operations whichare then brought about are as follows:

When the calling party inserts a 10 pfg. piece into the pay station thecontact gl0 is transiitorily closed. Relay X10 energized over itsWinding XIBI.

Relay X50 does not receive sufiicient current to energize. Rotary magnetDWIO is energized over the contact Iazl0.

(2) Earthl.rl 0-DWI 0--battery.

The rotary magnet DW|0 drives the wipers of the fee selector W10 forwardby one step. This selector Wl0 has three wipers Wl0I, WIUII, WIO'III andpossesses 35 steps 1-35 and one resting step 1'. During the insertion ofthe 22 10 pfg. pieces the fee selector W|0 is set to step 22. On theinsertion of the 50 pig. piece relays Xl0 and X50 are energized.

The rotary magnet DW50 is energized over contact Iw50.

(4) Earthl.r50DW50--battery.

The fee selector W50 possesses three wipers W50IW50III. The number ofsteps amount to 11 and one resting step T. On the insertion of the 50pfg. pieces the fee selector WI 0 is also displaced by one step throughthe energizing of relay Xl0. After the insertion of the amount of 2.70marks the fee selector Will is thus standing on step 23 according to thepresent example and the fee selector W50 on step l. On taking up thereceiver contact IHU is closed so that relay A pulls up in the followingcircuit:

Relays Xl0 and X50 do not energize in this circuit since their windingsI and II are arranged differentially. By means of the energizing ofrelay A a free group selector is seized. Over contact 3a. rotary magnetDVW of the preselector is started up in the known manner. As soon as thepreselector VW has seized the group selector, relay T energizes and bymeans of contact It disconnects the rotary magnet DVW from the relayinterrupter RU. The feeding relays AG and BG in the group selector GWremain energized over contact la. By means of contact 20. theslow-to-release relay V is energized.

(6) Earth-2wVlbattery.

On transmitting the first selecting impulse relay A deenergizes duringthe opening of impulse contact nsi. Since relay VI is slow-to-releaserelay D energizes over its winding DI in the following circuit:

(7) Earth2a l e-l vl-DI-battery.

Relay D locks up over its winding DII over circuit.

(8) Earth--d-2tDII-battery.

By means of contacts Id and 2d the lines are connected to the impulserelay E and, at the same time, the fee impulse relays Xl0 and X50 aredisconnected. Relay E serves as feeding relay for the microphone Ms andpossesses two windings EI and E11. Microphone feeding over relays Xl0and X50 would be unpractical since on account of the necessary highresistance of these relays lthe microphone feeding current would be toosmall. As soon as the impulse contact 1281 again closes relay Eenergizes.

Zd-EII-battery. Over contact le relay VI is maintained energized. Therotary magnet DMW of the discriminating switch MW energizes over contact3e. The discriminating switch MW has three wipers MWI-III and possesses20 contacts and one resting contact T. On dialling the characterizingdigit 0 the discriminating switch MW is set on contact 0. On commencingto dial, an operation which is conveniently characterized by theenergizing of relay D, the control switch is displaced from position 0to position 1. The wipers of the control switch are represented in theusual way by roman numerals in combination with arabic numerals. Thearabic numerals indicate the position of the control switch. The rotarymagnet of the control switch is indicated by DST. On the first settingimpulse the rotary magnet DST is energized in the following circuit:

(10) Earth--6d-I0 of the control switch- DST-battery. As soon as thecontrol switch has reached position 1 the auxiliary selector HW iscaused to take up the complementary steps of the fee selector W50. Therotary magnets DHW and DW50 runs synchronously until the wiper W501 hasreached the rest position 1'.

(11) Earth-RU-W50I on contacts 1-1l-- control switch IIIlDH50--battery.Earthcontacts of the fee selector lW50-control switch I i DHW-battery.

When the fee selector W50 has reached the rest position r the auxiliaryselector I-IW is standing on contact 10 i. e. 1l--l. The contacts whichare brushed by wiper I-IWI are wired to the contacts of the totallingswitch SW which are brushed by wiper SWI, in such a manner that contact11 of HW is connected to contact 0 of SW1, contact 10 of HW is connectedto contact 4 of SWI, contact 9 of HW is connected to contact 8 of SWIand so on. In this manner the fee recorded in selector W50 is convertedinto 10 pfg. units, while at the same time the value transmitted to thefee selector Will, produced by the simultaneous energizing of XID andX50 when contact g5ll is closed, is subtracted.

As soon as the auxiliary selector HW has taken up the complementarysteps of W50 the control switch is advanced to position 2. The rotarymagnet DST of the control switch energizes in the followingcircuit:

(l2) EarthW5UII-contact 1'control switch II lDST--battery. The totallingswitch SW must now be displaced to the contact which is connected tothat contact on which the auxiliary selector HW is set. The rotarymagnet DSW receives current from the interrupter over wiper I of thecontrol switch in position II, in thefollowing circuit:

(13) Earth-relay interrupter DSWbattery. 1 As soon as wiper SWI hasreached contact 4 relay Q energizes:

(14) Earth-contact III2 of the control switchcontact 10 of HWI-contact 4of SWI- Q-battery. The rotary magnet DST of the control switch is againenergized over wiper 2a and wiper II of the control switch in position2so that the control switch proceeds to position 3. The advancing circuitfor DSW is accordingly interrupted. In order to take over the setting offee selector Will the auxiliary selector HW must now be advanced to therest position. This is effected over the following circuit:

(15) EarthRU-HWII on contact 10-control switch I3--DHW-battery. As soonas the auxiliary selector HW hasreached its rest position the rotarymagnetDST energizes over wiper HWV and wiper II in position 3 (16)Earth-HWV in position rII3-DST- battery. I The rotary magnet DHW is nowdriven synchronously with the rotary magnet DWIO until the selector WI!)reaches its rest position.

(17) Earth-RU-contacts 1-35 of WWI- III4--DW|U-battery, andearth-contacts of the fee selector IWl-I4-DHWbatt ery. The auxiliaryselector HW has now taken over the complementary steps from Will. It isnow on contact-13, i. e. 3623. As soon as Will has reached the restposition the magnet DST of the control switch is again energized overthe circuit:

(18) EarthWl0II on contact rII4-DST-- battery. The control switch is nowin position 5. In this position the totalling switch is again set inmotion and takes over the complementary steps from the auxiliaryselector HW. The rotary magnets DHW and DSW are operated synchronouslyin the following circuit:

(19) Earth-RUHWIV on contacts 1-35- I--DSW--battery, and earth-RU-HWIVon contacts 1-5III5DHWbattery. The complementary steps of HW amount to36 113i. e. 23. The totalling switch SW is thus advanced from itsposition 4 by a further 23 steps and thus reaches contact 2'7. This corrsponds to the inserted fee of 2.70 marks in pfg. units.

The setting of the totalling switch SW is effected independently of thefurther operation of the selecting devices. As soon, therefore, as

the number of impulse trains corresponding to the call number of theconnection has been sent out, testing can take place as to whether thesetting of the discriminating switch MW corresponds with the setting ofthe totalling switch SW. On transmitting the first dialled impulse thediscriminating switch MW was displaced. During the impulse transmissionrelay V2 energizes in the following circuit:

( 20) Earth-2a- I e-- v l-V2-battery.

Relay V2 is slow-to-release. Accordingly at the end of the first impulsetrain relay RI pulls up.

(21) Earth-MWIII on contacts 1-20-|v2- Rl-battery.

On transmitting the second impulse train relay R2 energizes on accountof the slow-to-release feature of relay RI.

Relay R2 locks up over its contact I12 and the contact 273 and 1d. Afterthe totalling switch SW had been set on the contact corresponding to thetotal fee paid in, the control switch was advanced to position 6. Therotary magnet DST was energized in the following circuit:

(23) Earth-HWV on contact 1'-II5--DST battery. In position 6 of thecontrol switch relay F energizes if the position of the discriminatingswitch MW corresponds with the position of the totalling switch SW. Inthe present example the number 08 was characteristic of the call forwhich the sum of 2.70 marks had to be paid. The following circuit isaccordingly established:

(24) Earth-MWII on contact 08SWII on contact 27FI62r2-.battery.

In position 6 of the control switch the slow acting relay R3 draws up. i

(25) Earth R3I6-2r2-battery.

If the setting of switches -MW and SW do not correspond relay TR becomesenergized.

(26) Earth-2g-lr3- l jTR-battery. Relay TR locks up over contact Itr and4d. The connection set up is cut off by means of contact Ztr since thecontrol relays AG and BG of the group selector deenergize. If thecorrect fee has been introduced the energizing of relay TR is preventedby contact If. The rotary magnet DST of the control switch is againenergized through contact 3T3 as soon as relay R2 has deenergized, thelocking circuit of this relay being broken by contact 21-3.

(27) Earth-3r33 r 2I I 6 D S T-battery. The rotary magnet of the controlswitch is energized over wiper I in position 7 as soon as relay Dreleases. Relay D is deenergized by means of contact 2t when theconnection is released. On replacing the receiver the exchange loop isbroken by contact II-IU and relay E releases. The control relays AG andBG are deenergized by means of contact 2e and the first group selectorreleases. Relay T in the preselector deenergizes. The locking circuitfor relay D is broken by contact 2t. The preselector is returned to itsrest position over contact It in the known manner. Rotary magnet DSTdraws up over the circuit.

(28) Earth8d-I1-DST-battery.

When the called subscriber replies relay M receives an impulse over thefourth wiper of the pre-selector VM and locks up over contact 3t and itsown contact lm. On replacing the receiver the locking magnet SM iscaused to energize over contact ZHU in the pay station in the followingcircuit:

(29) EarthSM2HU2d-EII-battery.

By means of contact lsm the collecting magnet KM is connected tothea-lead and by means of contact (ism the high resistance winding SMII of-magnet SM is connected up. so that relay E canno longer remainenergized. As soon as relay E has released relay KR is energizedprovided that the called subscriber has replied.

(30) Earth-2 (1- e2 m-KRbattery.

Relay KR. locks up over its own contact 2hr and contact p. Thecollecting magnet KM and relay P energize over contact llcr. Contact pbreaks the locking circuit for relay KR. Relay KM causes the insertedfee to: be collected. If the subscriber has not replied the energizingof relay KR'is delayed. 'When the connection is released the controlswitch is advanced from position 7 to position 8 as already explained.The control switch is advanced into its rest position over wiper I andcontacts 8 and 9. (31) Earth-RU--I-8, 9-DST-battery. If the auxiliaryselector I-IW is not yet in the rest position it is advanced to the zeroposition over 1110 and HWIII. In the same way the totalling switch SW,the discriminating switch MW and the fee selectors Wlll and W50 areadvanced to the rest contact 1'.

If the calling party takes up his receiver before inserting the feerelay A energizes. This has the same efiect asthat already described. Ifthe contacts glll and 950 are closed when the receiver has, alreadybeenremoved this has no influence on the energizing of relay A becausethe ratio of the resistances in the branch circuits thus established isso chosen that relay A receives suflicient energizing current. It may bementioned that by the use of a corresponding call finder circuit it ispossible to use the discriminating switch HM, the totaling switch SW,the auxiliary selector HW and the control switch SW in common for alarger number of I pay stations, .since these switching devices are onlytransitorily operative during the setting up of a call. It is alsopossible to use the setting of the totalizing selector to set controlmeters associated with the paystation.

Local calls, for which a fee of 10 pig. is paid, are characterized byhaving no 0 in the first digit of the call number. Contacts l9 of thediscriminating switch are therefore connected with the 10 pfg. contactofv the totalling selec-, tor. It is also possible to provide for freecalls. In this case the contact of the discriminating switch MWcorresponding to the characterizing number of the free call -must beconnected to the zero-contact of the totalling switch so that in thiscase the release relay F can energize.

.As already explained long distance calls can also be set up from thepay station. and in this case the supervision of the fee which is to bepaid is effected by audible signals which are transmitted by way of themicrophone Mk. In order that these signals should not be distorted bythe-closing of contacts glll and 50 various measures must be taken toreduce the crackling sounds. This is efiected according to the inventionin that the earth potential for fee impulse signalling is connected upover a choke coil DR of high inductance which in turn is connected to. apoint approximating to the point of symmetry of the induction coil In.The fee impulse contacts glll and g50 are constructed as successivelyclosing contacts of which one contact spring which is arranged next tothe operating spring is connected to an earth condenser KI. Theasymmetry in the line produced by the operation of relay A in serieswith windings II of the fee impulse relays Klll and X50 is equalized bythe condenser K2.

In the case of free calls on dialling, for example, the digits 00 relayG is energized over MWII and by opening its contact lg prevents theenergizing of relay M when the called party replies. In this case theenergizing of the collecting relay KR is also prevented when thereceiver is replaced. Contact 29 prevents the energizing of relay TR sothat no disconnection is brought about by the fee testing.

What is claimed is:

1. In an automatic telephone system, a paystation telephone connected bya line to the exchange, a calling device for transmitting impulses tothe exchange to extend a connection to a desired subscriber, adiscriminating switch also responsive to said calling device impulses,coin operated contacts at said paystation, a different resistanceconnected to said line by each of said contacts responsive to thepassage of corresponding coins in said paystation, coin relays in saidline each responsive to the connection of a particular resistance tosaid line, coin switches at said exchange each operated by an associatedcoin relay, and means for permitting the extension of the call only inthe event that the positions to which said discriminating switch andsaid coin switches are operated correspond to the value and destinationof the call.

2. In a paystation telephone system as claimed in claim 1 in which thecoin contacts operate thecoin relays by connecting ground impulses overthe difierent resistances to one side of the line, while the callingdevice impulses are transmitted over the line in series.

3. In a paystation telephone system as claimed in claim 1 in which thecoin relays are difierentially arranged in series with each other andconnected to opposite sidesof the line and in which the coin contactsoperate the correspondingcoin relay by connecting ground impulses to oneside of theline through the corresponding resistance to operate only theassociated coin relays, and in which an impulse relay is connected inseries with said coin relays and is only responsive to dial impulsestransmitted over both sides of said line in series.

4. In an automatic telephone system, a paystation telephone connectedover a line to the exchange, a calling device at said paystation fortransmitting impulses over the line in series to the exchange in orderto establish a connection with another subscriber, coin contacts at saidpaystation operated by the passage of coins thereat, a difierentresistance connected to ground potential through each of said coincontacts by the passage of the coins in order to transmit coin impulsesover one side of the line, a differential coin relay for each of saidcoin contacts and each relay having a different energizingcharacteristic, an impulse relay responsive only to dial impulsestransmitted in series over the line, a discriminiating switch operatedby said impulse relay, a coin switch operated by each of saiddifferential coin relays, and means whereby a connection is extended toa desired subscriber only in case the discriminating switch and the coinswitches are set to positions corresponding to the particular feerequired and the impulse series associated with the location of thewanted subscriber.

5. In a paystation telephone system as claimed in claim 4. in which atotalling switch is provided to add the fee sum of the settings of thecoin switches in order to determine whether the connection to the wantedsubscriber is to be extended.

6. In a paystation telephone system as claimed in claim 4, an auxiliaryswitch and a totalling switch at said exchange, said auxiliary switchautomatically operated to a position corresponding to the position ofone of said coin switches and then the other, said totalling switchthereby operated to the position assumed by said auxiliary switch, saidtotalling switch converting the coin values into unit coin values fromthe first of said coin switches and subtracting the values of thesetting of the other of said coin switches therefrom, the bank contactsof said auxiliary switch and said totalling switch being correspondinglywired together to efiect the conversion value.

7. In a paystation telephone system as claimed in claim 4, an auxiliaryswitch and a totalling switch, said auxiliary switch first operated totransmit the setting of one of said coin switches to said totallingswitch and then releasing, then operated to the position of the othercoin switch and transmitting the setting of said coin switch to saidtotalling switch during the release of the auxiliary switch.

8. In a paystation telephone system as claimed in claim 1 in which thecoin relays are disconnected from the line circuit after the connectionhas been extended.

9. In a paystation telephone system as claimed in claim 1 in whichcrackling noises and disturbances to a listening operator caused by theinsertion of coins are reduced by connecting ground potential throughthe resistances and the coin contacts to the approximate center point ofthe paystation induction coil through a chokeooil, and by a condenser incircuit with the coin contacts and another condenser in circuit with thedial impulse relay of the line circuit.

FRITZ APPELIUS.

